[英]How to create a transparent shape in the image
因此,以下使用:
ImageIO
API 所以,从这个开始...
我想在它后面添加它(但可以窥视一下)
我们需要做的第一件事是为要变得透明的区域制作一个基于“ alpha”的蒙版。 为此,我使用了RadialGradientPaint
,因为它允许我在边缘周围产生“褪色”效果。
现在,我已经完成了所有的数学运算(使用一个简单的图像编辑器进行计算),所以我知道我希望“孔”出现在哪里
BufferedImage city = ImageIO.read(new File("/Users/swhitehead/Downloads/City.jpg"));
BufferedImage mask = new BufferedImage(city.getWidth(), city.getHeight(), BufferedImage.TYPE_INT_ARGB);
Graphics2D g2d = mask.createGraphics();
Color transparent = new Color(255, 0, 0, 0);
Color fill = Color.RED;
RadialGradientPaint rgp = new RadialGradientPaint(
new Point2D.Double(955, 185),
185,
new float[]{0f, 0.75f, 1f},
new Color[]{transparent, transparent, fill});
g2d.setPaint(rgp);
g2d.fill(new Rectangle(0, 0, mask.getWidth(), mask.getHeight()));
g2d.dispose();
接下来,我们使用AlphaComposite
在原始(城市)图像上绘制蒙版...
BufferedImage masked = new BufferedImage(city.getWidth(), city.getHeight(), BufferedImage.TYPE_INT_ARGB);
g2d = masked.createGraphics();
g2d.setColor(Color.RED);
g2d.fillRect(0, 0, masked.getWidth(), masked.getHeight());
g2d.drawImage(city, 0, 0, null);
g2d.setComposite(AlphaComposite.DstAtop);
g2d.drawImage(mask, 0, 0, null);
g2d.dispose();
这会产生类似...
“白色”孔实际上是透明的,只是页面也是白色的:/
最后,我们将masked
图像与背景图像结合起来...
BufferedImage composite = new BufferedImage(city.getWidth(), city.getHeight(), BufferedImage.TYPE_INT_ARGB);
g2d = composite.createGraphics();
g2d.drawImage(background, city.getWidth() - background.getWidth(), 0, null);
g2d.drawImage(masked, 0, 0, null);
g2d.dispose();
产生类似...的东西
所以,根据您的描述,这就是我的意思
从这里 :
# import the necessary packages
from __future__ import print_function
import numpy as np
import cv2
# load the image
image = cv2.imread("pic.jpg")
# loop over the alpha transparency values
for alpha in np.arange(0, 1.1, 0.1)[::-1]:
# create two copies of the original image -- one for
# the overlay and one for the final output image
overlay = image.copy()
output = image.copy()
# draw a red rectangle surrounding Adrian in the image
# along with the text "PyImageSearch" at the top-left
# corner
cv2.rectangle(overlay, (420, 205), (595, 385),
(0, 0, 255), -1)
cv2.putText(overlay, "PyImageSearch: alpha={}".format(alpha),
(10, 30), cv2.FONT_HERSHEY_SIMPLEX, 1.0, (0, 0, 255), 3)
# apply the overlay
cv2.addWeighted(overlay, alpha, output, 1 - alpha,
0, output)
# show the output image
print("alpha={}, beta={}".format(alpha, 1 - alpha))
cv2.imshow("Output", output)
cv2.waitKey(0)
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